Experimental study of single-phase flow and heat transfer in rectangular channels under uniform and non-uniform heating

Sun, Rulei; Song, Gongle; Zhang, Dalin; Deng, Jian; Su, G.H.; Kulacki, F. A.; Tian, Wenxi; Qiu, Suizheng

doi:10.1016/j.expthermflusci.2020.110055

Cited by 20 publications

(4 citation statements)

References 43 publications

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“…In the zones of efficient heat transfer enhancement, the local wall temperature has the tendency to reach the fluid bulk temperature, thus causing a hyperbolic increment of the local heat transfer coefficient, as visible in Figure . This behavior is better seen on 2D maps, showing the percentage difference from the average heat flux and convective coefficient, as in 7. While being partially beyond the scope of the paper, the resulting Nu/Nu0 maps with respect to the smooth configuration, given by the correlations reported in [13], is shown in figure 8 for Re equal to 670, 2150 and 7500.…”

Section: Resultsmentioning

confidence: 99%

“…In addition to these points, also in the light of the considerations by Moffat on single-sample experiments [12], in studies like the one presented here, it can be totally misleading to provide a "certain" uncertainty value, based on uncertainties of the single measurement devices, as many uncertainty sources in complex experiments, like focus position, environmental conditions, and the positioning of the IR camera, can be easily overlooked, and the best way to validate the results is by cross-comparison with different numerical and experimental techniques applied to the same problem. Also, literature data in simple test cases can be a valuable benchmark, but is more useful to verify trends rather than exact values, which may depend on the specific experimental setup, as shown for example in figure 3 from Sun et al [13], where various trends for the heat transfer characteristics of rectangular channels are shown in a single graph. Measurement uncertainties are due to temperature sensors, IR-camera, and mass-flow-rate meter.…”

Section: Uncertainty Analysismentioning

confidence: 99%

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Heat fluxes distribution and uncertainty in low-Reynolds flow regimes inside a ribbed channel

Vitali

Gramazio

Fustinoni

et al. 2022

J. Phys.: Conf. Ser.

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Experimental studies on the local convective heat transfer enhancement induced by ribs in channels are generally carried out in steady state, by imposing a known heat flux on the ribbed surface and subsequently retrieving the convective heat flux by means of a local heat balance, i.e. by subtracting all the non-convective heat fluxes from the source term. Such heat fluxes are retrieved from temperature measurements by means of models, whose complexity can range from simple algebraic expressions to complex simulations. In this context, an experimental technique based on FEM simulations, a radiative model for semi-transparent enclosures, and a filtering technique to retrieve the heat fluxes across the plane of the heated surface has been developed and tested in a 1:10 AR channel, for Reynolds number ranging from 650 to 7500 and a flow of air. This paper presents a discussion on the heat flux distribution as a function of the Reynolds number for a streamwise-pointing chevron (V) rib configuration with 60° angle of attack, with P/e = 20, showing the increasing weight of non-convective heat dissipations as the Reynolds number decreases, and their effect on the uncertainty of the Nusselt number measurement.

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Section: Resultsmentioning

confidence: 99%

Section: Uncertainty Analysismentioning

confidence: 99%

Heat fluxes distribution and uncertainty in low-Reynolds flow regimes inside a ribbed channel

Vitali

Gramazio

Fustinoni

et al. 2022

J. Phys.: Conf. Ser.

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“…Chen et al [26] used the inverse approach to compute the heat transfer coefficient of a rectangular heat sink with different fin spacing. Sun et al [27] investigated heat transfer from rectangular channels using water as the fluid under uniform and non-uniform heating and derived correlations for laminar and transition regions up to Re = 10.000.…”

Section: Introductionmentioning

confidence: 99%

Natural and Forced Convective Heat Transfer Enhancement for Solid Cylinders with Different Geometrical Shapes

Rafi,

Rahman,

Rabby

et al. 2024

Period. Polytech. Mech. Eng.

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Enhancing heat transfer for both natural and forced convection is a common issue for any heat transfer process. Experimental studies have been carried out for six different geometrical shapes of solid bars for natural convection and forced convection with four different air velocities while keeping the same perimeter and length of the solid bars, which means the lateral surface area of the bars is the same. Results reveal that both the natural and forced convective heat transfer characteristics are greatly influenced by the geometrical shape in terms of Nusselt number (Nu), heat transfer coefficient (h), and heat transfer rate (q). In addition, isosceles and cylindrical shape geometry contribute to the lowest and highest heat transfer, respectively. As well, it is obtained from the results that convective heat transfer characteristics are directly related to the cross-sectional area, even if the perimeters are the same. Moreover, among the different geometrical shapes, the isosceles and hexagonal shapes take the shortest and longest duration to attain the steady-state condition in the conductive heat transfer process. The convective heat transfer characteristics are well-validated, with available results for both natural and forced convection heat transfer.

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“…The research of heat transfer of the fuel assembly is fundamental for improving the safety, reliability and economy. However, the coolant flow and heat transfer characteristics in the narrow rectangular channels are significantly different from those of conventional channels and tubes (Sun et al, 2020). Therefore, investigation of coolant flow and heat transfer characteristics in the plate-type fuel assembly is important for research reactors designing.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of Conjugated Heat Transfer of the Plate-Type Fuel Assembly in the Research Reactor

Quan

et al. 2021

Front. Energy Res.

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In nuclear reactors, the research of conjugated heat transfer between the fuel and coolant in the fuel assembly is fundamental for improving the safety, reliability and economy. The numerical approach based on Computational Fluid Dynamics (CFD) can be used to realize the rapid analysis of the conjugated heat transfer. Besides, the numerical simulation can provide detailed physical fields that are useful for the designing and optimizing of the fuel assembly. The plate-type fuels are generally used to enhance heat transfer in research reactors with high power density. In this study, a standard plate-type fuel assembly in the research reactor was taken into consideration. The solid-fluid conjugated heat transfer of the fuel assembly and coolant was numerically investigated. In the fluid region, the subcooled flow boiling simulation model was established by implementing the Rensselaer Polytechnic Institute model into the Euler multi-phase flow method. The results show that the conjugated heat transfer of the fuel assembly and coolant can be simulated using the model established in this work. The influence of fluid velocity, power density and the width of the flow channel on the temperature distribution and the conjugated heat transfer was investigated and discussed.

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Experimental study of single-phase flow and heat transfer in rectangular channels under uniform and non-uniform heating

Cited by 20 publications

References 43 publications

Heat fluxes distribution and uncertainty in low-Reynolds flow regimes inside a ribbed channel

Heat fluxes distribution and uncertainty in low-Reynolds flow regimes inside a ribbed channel

Natural and Forced Convective Heat Transfer Enhancement for Solid Cylinders with Different Geometrical Shapes

Numerical Investigation of Conjugated Heat Transfer of the Plate-Type Fuel Assembly in the Research Reactor

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